Electro-optical device and electronic apparatus

ABSTRACT

An electro-optical device includes a scanning line, a data line intersecting with each other, a pixel circuit which is provided corresponding to the intersection thereof, and a wire. The pixel circuit includes a light emitting element, one transistor which controls a current flowing to the light emitting element, and the other transistor of which conduction state is controlled according to a scanning signal which is supplied to the scanning line between a gate node of the one transistor and the data line. The wire is provided between the data line and the one transistor.

This application claims priority to JP 2011-053562 filed Mar. 10, 2011,the disclosure of which is hereby incorporated by reference herein inits entirety.

BACKGROUND

1. Technical Field

The present invention relates to an electro-optical device and anelectronic apparatus.

2. Related Art

In recent years, various electro-optical devices in which a lightemitting element such as an Organic Light Emitting Diode (hereinafter,referred to as “OLED”) is used have been proposed. In such anelectro-optical device, a pixel circuit is provided corresponding to theintersection of a scanning line and a data line. In general, the pixelcircuit includes the above described light emitting element, a switchingtransistor, and a driving transistor (refer to JP-A-2007-310311). Here,the switching transistor is turned on in a selection period of thescanning line, between the data line and a gate of the drivingtransistor, and in this manner, an electric potential which is suppliedto the data line is held in the gate. In addition, the drivingtransistor is configured to flow a current corresponding to a holdingpotential of the gate to the light emitting element.

Meanwhile, in a usage in which miniaturization of the size of a displayand higher resolution of the display are necessary, the data line andthe driving transistor are close to each other, and the degree ofcapacitative coupling is increased. For this reason, when there ispotential fluctuation of the data line, the potential fluctuationpropagates to each portion of the driving transistor, especially to thegate as a kind of noise, through parasitic capacitance, and causes theholding potential of the gate to fluctuate. Accordingly, there was aproblem in that the display quality is degraded, since it was notpossible to flow a desired current to the light emitting element.

SUMMARY

An advantage of some aspects of the invention is to prevent the displayquality from being degraded due to noise which is caused by thepotential fluctuation of the data line.

According to an aspect of the invention, there is provided anelectro-optical device which includes, scanning lines and data lineswhich intersect with each other; pixel circuits which are providedcorresponding to the intersection of the scanning lines and the datalines; and a shield wires, wherein each of the pixel circuit includes alight emitting element, a driving transistor which controls a currentflowing to the light emitting element, and a switching transistor whichis connected between a gate of the driving transistor and the data line,and of which conduction state is controlled according to a scanningsignal which is supplied to the scanning line, and wherein each of theshield wires is provided between the data line and the drivingtransistor when seen in the plan view.

According to the aspect of the invention, the noise which is generatedfrom the data line is absorbed by the shield wire before reaching thedriving transistor of the pixel circuit. For this reason, the drivingtransistor is hardly influenced by noise or the like, therefore, it ispossible to prevent the display quality from being degraded.

According to the aspect of the invention, it is preferable that thedistance between the shield wire and the data line be shorter than thedistance between the shield wire and the driving transistor. Accordingto the aspect, it is possible to more reliably suppress the influence bythe noise or the like.

According to the aspect of the invention, regarding the shield wire,even if it is in a high impedance state (floating) which is notelectrically connected to a certain portion, it is possible to absorbthe noise, for example, when capacitative coupling is performed to aelectric supply line of a constant potential in time, however, it ispreferable that be directly connected to the constant potential in time.In this configuration, in the pixel circuit, the light emitting elementand the driving transistor are connected to each other in series in apath between the power line on the high side and the power line on thelow side, and if the shield wire is connected to the high side powerline, or to the low side power line, it is sufficient if it is connectedto an existing power line.

In addition, in such a configuration, in the pixel circuit, if theshield wire has a portion which is connected to the high side power lineor the low side power line, it is possible to more reliably absorb thenoise, since the shield wire can be made to have low impedance.

Further, according to the aspect of the invention, it is preferable tohave a holding capacity of which one end is electrically connected tothe gate of the driving transistor. In this configuration, if the shieldwire is set to cover the holding capacity when seen in the plan view, itis possible to make a holding voltage due to the holding capacitydifficult to be influenced by noise.

In addition, according to another aspect of the invention, there isprovided an electro-optical device which includes, scanning lines anddata lines which intersect with each other; pixel circuits which areprovided corresponding to each the intersection of the scanning linesand the data lines; and shield wires, wherein each of the pixel circuitincludes a light emitting element, a driving transistor which controls acurrent flowing to the light emitting element, and a switchingtransistor which is connected between a gate of the driving transistorand the data line, and of which conduction state is controlled accordingto a scanning signal which is supplied to the scanning line, and whereinthe shield wire is provided between the data line and the drivingtransistor in the cross-sectional view, and may be obtained by aconfiguration in which the shield wire is overlapped with at least apart of the data line or the driving transistor when seen in the planview.

In addition, the electro-optical device according to the aspect of theinvention may be applied to various electronic apparatuses. Typically,they are display devices, and as an electronic apparatus, for example,there is a personal computer or a mobile phone. Especially, in theapplication, even when the holding capacity is not sufficiently secure,the noise from the data line is absorbed to the shield wire beforereaching the driving transistor of the pixel circuit, and due to this,it is possible to prevent the quality of the display from beingdegraded. Accordingly, for example, it is preferable to be applied to adisplay device which forms a reduced image such as a display device fora head-mounted display or a projector. The usage of the electro-opticaldevice according to the aspect of the invention is not limited to thedisplay device. For example, it may be applied to an exposure device(optical head), as well, which forms a latent image on an image carriersuch as a photoconductive drum by irradiating a light beam.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described with reference to the accompanyingdrawings, wherein like numbers reference like elements.

FIG. 1 is a block diagram which shows a configuration of anelectro-optical device according to a first embodiment of the invention.

FIG. 2 is a diagram which shows an equivalent circuit of a pixel circuitin the electro-optical device.

FIG. 3 is a diagram which shows a display operation of theelectro-optical device.

FIG. 4 is a plan view which shows a configuration of the pixel circuit.

FIG. 5 is a partial cross-sectional view which shows the configurationin FIG. 4 which is cut along line V-V.

FIG. 6 is a diagram which shows absorption of noise from a data line inthe pixel circuit.

FIG. 7 is a diagram which shows a variety of parasitic capacitances inthe pixel circuit.

FIG. 8 is a diagram in which the variety of parasitic capacitances inthe pixel circuit are modeled.

FIGS. 9A and 9B are diagrams which show an example of crosstalk.

FIG. 10 is a plan view which shows a configuration of a pixel circuit ofan electro-optical device according to a second embodiment of theinvention.

FIG. 11 is a partial cross-sectional view which shows the configurationin FIG. 10 which is cut along line XI-XI.

FIG. 12 is a plan view which shows a configuration of a pixel circuit ofan electro-optical device according to a third embodiment of theinvention.

FIG. 13 is a partial cross-sectional view which shows the configurationin FIG. 12 which is cut along line XIII-XIII.

FIG. 14 is a plan view which shows a configuration of a pixel circuit ofan electro-optical device according to a fourth embodiment of theinvention.

FIG. 15 is a plan view which shows a configuration of a pixel circuit ofan electro-optical device according to a fifth embodiment of theinvention.

FIG. 16 is a plan view which shows a configuration of a pixel circuit ofan electro-optical device according to a sixth embodiment of theinvention.

FIG. 17 is a partial cross-sectional view which shows the configurationin FIG. 16 which is cut along line XVII-XVII.

FIG. 18 is a plan view which shows a configuration of a pixel circuit ofan electro-optical device according to a seventh embodiment of theinvention.

FIG. 19 is a diagram which shows an equivalent circuit of a pixelcircuit according to a different example.

FIG. 20 is a diagram which shows an electronic apparatus (the one) towhich the electro-optical device is applied.

FIG. 21 is a diagram which shows an electronic apparatus (the two) towhich the electro-optical device is applied.

FIG. 22 is a diagram which shows an electronic apparatus (the three) towhich the electro-optical device is applied.

DETAILED DESCRIPTION OF EMBODIMENTS First Embodiment

FIG. 1 is a block diagram which shows a configuration of anelectro-optical device according to a first embodiment of the invention.The electro-optical device 1 is a device for displaying an image using aplurality of pixel circuits 110.

As shown in the drawing, the electro-optical device 1 includes anelement unit 100, a scanning line driving circuit 210 and a data linedriving circuit 220.

Among these, in the element unit 100, m rows of scanning lines 112 areprovided in the row (X) direction, and n columns of data lines 114 areprovided in the column (Y) direction in the drawing so as to maintainelectrical insulation with respect to each of the scanning lines 112,each other. The pixel circuit 110 is respectively arranged correspondingto each intersection between the m rows of scantling lines 112 and the ncolumns of data lines 114. Accordingly, in the embodiment, the pixelcircuit 110 is arranged in matrix of vertical m rows x horizontal ncolumns. In addition the number m and n are all natural numbers.

Respective power lines 116 are commonly connected to each of the pixelcircuits 110, and a potential Vel on the high side of device power issupplied thereto. In addition, although omitted in FIG. 1, as will bedescribed later, a common electrode is provided over each of the pixelcircuits 110, and a potential Vct on the low side of the device power issupplied thereto. These potentials Vel and Vct are generated by a powersupply circuit which is not shown.

In addition, in order to distinguish the row of the scanning line 112from the row of the pixel circuit 110 conveniently, there may be a casewhere the rows are called sequentially from above a first row, a secondrow, a third row, . . . , (m−1)th row, and mth row in FIG. 1. Similarly,in order to conveniently distinguish the column of the data line 114from the column of the pixel circuit 110, there may be a case where thecolumns are called sequentially from above a first column, a secondcolumn, a third column, . . . , (n−1)th column and nth column in FIG. 1.

In the electro-optical device 1, the scanning line driving circuit 210and the data line driving circuit 220 are arranged in the vicinity of aregion where the pixel circuits 110 are arranged in matrix. Theoperations of the scanning line driving circuit 210 and the data linedriving circuit 220 are controlled by a controller which is not shown.In addition, gray scale data which designates gray scale (brightness) tobe expressed in each of the pixel circuits 110 is supplied to the datadriving circuit 220 from the controller.

The scanning line driving circuit 210 is a circuit which sequentiallyselects the row of scanning lines 1 to m in each frame. For example, thescanning line driving circuit 210 is the circuit which suppliesrespective scanning signals of Gwr (1), Gwr (2), Gwr (3), . . . , Gwr(m−1), Gwr(m) to the scanning lines of the first row, the second row,the third row, . . . , (m−1)th row, and mth row, and sequentially setseach of the scanning lines in the frame to H level, exclusively. In thisdescription, the frame means the time period which is necessary todisplay an image of one cut (frame) in the electro-optical device 1, andif the vertical scan frequency is 60 Hz, it is a time period of 16.67milliseconds of one cycle thereof.

The data line driving circuit 220 is a circuit which supplies a datasignal of a potential corresponding to the gray scale data of the pixelcircuit 110, with respect to the pixel circuit 110 which is positionedon a row which is selected by the scanning line driving circuit 210,through the data line 114. For the sake of convenience, the data signalswhich are respectively supplied to the data lines 114 of the firstcolumn, a second column, a third column, . . . , (n−1)th column and nthcolumn are denoted by Vd (1), Vd (2), Vd (3), . . . , Vd (n−1), and Vd(n).

Subsequently, the equivalent circuit of the pixel circuit 110 will bedescribed with reference to FIG. 2. In addition, in FIG. 2, pixelcircuits 110 are shown arranged 2×2 for a total of four pixels, whichcorresponds to intersections of the scanning lines 112 of ith row and(i+1)th row which neighbors the ith row from below, and the data lines114 of jth column and (j+1)th column which neighbors the jth column onthe right. Here, the i and (i+1) are symbols which are used whengenerally showing the columns in which the pixel circuits 110 arearranged, and the symbols are integers of equal to 1 or more and equalto n or less. Similarly, the j and (j+1) are symbols which are used whengenerally showing the columns in which the pixel circuits 110 arearranged, and the symbols are integers of equal to 1 or more and equalto n or less.

As shown in FIG. 2, each pixel circuit 110 includes transistors 130 and140 of N-channel-type, a holding capacity 135, and a light emittingelement 150. Since each of the pixel circuits 110 has the sameconfiguration as each other, the pixel circuit on the ith row and thejth column will be representatively described. In the pixel circuit onthe ith row and the jth column, the transistor 130 functions as aswitching transistor, and a gate node thereof is connected to thescanning line 112 on the ith row. On the other hand, a drain nodethereof is connected to the data line 114 on the jth column, and asource node thereof is connected to one end of the holding capacity 135,and to a gate node of the transistor 140, respectively.

The other end of the holding capacity 135 is connected to a source nodeof the transistor 140 and an anode of the light emitting element 150,respectively. On the other hand, a drain node of the transistor 140 isconnected to the power supply line 116.

For the sake of convenience, in the pixel circuit 110 of ith row and jthcolumn, the drain node of the transistor 130 is denoted by a capitalletter of D, the gate node of the transistor 140 (a source node of thetransistor 130 and one end of the holding capacity 135) is denoted by asmall letter g. Particularly, the gate node of the transistor 140 on theith row and jth column is denoted by g(i, j).

In addition, the drain node (power supply line 116) of the transistor140 is denoted by a small letter d, and a source node of the transistor140 (an anode of the light emitting element 150) is denoted by a smallletter s.

The cathode of the light emitting element 150 is connected to a commonelectrode 118 in each of the pixel circuits 100. The common electrode118 is common to the light emitting element 150 of each pixel circuit110. The light emitting element 150 is an OLED which interposes alight-emitting layer which is formed of an organic EL material, betweenthe anode and cathode which face each other. The light emitting elementemits light with a brightness which corresponds to a current which flowsfrom the anode toward the cathode.

In addition, in FIG. 2, Gwr (i) and Gwr (i+1) denote scanning signalswhich are respectively supplied to scanning lines 112 of ith row and(i+1)th row. Further, Vd (j) and Vd (j+1) denote data signals which arerespectively supplied to data lines 114 of jth column and (j+1)thcolumn.

In addition, according to the embodiment, a shield wire is provided inthe vicinity of the data line 114, however, the shield wire will bedescribed in detail later.

Subsequently, a display operation of the electro-optical device 1 willbe simply described with reference to FIG. 3. FIG. 3 is a diagram whichshows an example of a waveform of the scanning signal and the datasignal.

As shown in the drawing, the scanning signals Gwr (1), Gwr (2), Gwr(3),Gwr (m−1), and Gwr(m) are sequentially set to (H) level exclusively, forevery horizontal scanning period (H) in each frame by the scanning linedriving circuit 210.

Here, when the ith row scanning line 112 is selected, and the scanningsignal Gwr (i) is set to (H) level, a data signal Vd (j) of a potentialwhich corresponds to gray scale data of the pixel circuit 110 on the ithrow and jth column is supplied by the data line driving circuit 220 inthe date line 114 on the jth column.

When the scanning signal Gwr (i) is set to H level in the pixel circuit110 on the ith row and jth column, since the transistor 130 is turnedon, the gate node g (i, j) is electrically connected to the data line114 on the jth column. For this reason, the potential of the gate node g(i, j) becomes the potential of data signal Vd (j) as denoted by an uparrow in FIG. 3. At this moment, the transistor 140 flows a currentwhich corresponds to the current of the gate node g (i, j) to the lightemitting element 150, and the holding capacity 135 holds a voltagebetween the gate and source in the transistor 140 at this moment. Whenthe selection of the scanning line 112 on the ith row is ended, and thescanning signal Gwr (i) becomes L level, the transistor 130 is turnedoff.

Even if the transistor 130 is turned off from the on state, the voltageof the transistor 140 between the gate node and the source node when thetransistor 130 is turned on is held by the holding capacity 135. Forthis reason, even if the transistor 130 is turned off, the transistor140 continuously flows a current corresponding to the hold voltage bythe holding capacity 135 to the light emitting element 150, until thenext scanning line 112 on the ith row is selected again. For thisreason, the light emitting element 150 in the pixel circuit 110 on theith row and jth column continuously emits light during the periodcorresponding to one frame with a brightness corresponding to apotential of data signal Vd (j) at the time of selecting the ith row,that is, with a brightness corresponding to the gray scale data of theith row and jth column.

In addition, in the ith row, the light emitting element emit lights witha brightness corresponding to a potential of a data signal which hasbeen supplied to the corresponding data line 114, even in a pixelcircuit 110 other than the jth column. Further, a pixel circuit 110corresponding to the scanning line 112 on the ith row is described here,however, the scanning line 112 is selected in order of the first row,the second row, the third row, . . . , the (m−1)th row, and the mth row.As a result, each of the pixel circuits 110 emits light with abrightness corresponding to the gray scale data, respectively. Such anoperation is repeated for every frame.

In addition, in FIG. 3, potential scales of the data signal Vd (j) andthe gate node g (i, j) are conveniently enlarged, compared to apotential scale of the scanning signal.

Meanwhile, since the data signal has a potential corresponding to thegray scale data of a pixel which is positioned on the selected row, thedata line 114 is subject to potential fluctuation every second accordingto the display content. For example, since the data signal Vd (j) asshown in FIG. 3 is supplied to the data line 114 on the jth column, thepotential fluctuates for every horizontal scanning period (H).

When the data line 114 performs capacitative coupling with each part ofthe pixel circuit 110, the potential fluctuation of the data line 114has a negative influence on the potential of each part of the pixelcircuit 110. Particularly, when a smaller size and higher resolution ofthe display is required, and for example, in a micro display for whichthe display size is less than one inch in diagonal, and the resolutionis 1280×720 pixels or more, the negative influence is prominent, sincethe parasitic capacitance of each part is relatively large compared tothe holding capacity 135. Particularly, the potential of the gate node gand source node s of the transistor 140 define a current which flows tothe light emitting element 150, the potential fluctuation of this partgenerates a garbled display or crosstalk which will be described later,and causes a serious degradation of a display quality.

Therefore, according to the embodiment, the pixel circuit 110 isconfigured as follows, and it is difficult to be influenced by noise dueto the potential fluctuation of the data line.

The structure of the pixel circuit 110 will be described with referenceto FIGS. 4 and 5.

FIG. 4 is a plan view which shows a configuration of four pixel circuits110 which are close to each other in the vertical and horizontaldirections. FIG. 5 is a partial cross-sectional view of the pixelcircuit in FIG. 4 which is cut along line V-V.

In addition, FIG. 4 shows a wiring structure of the pixel circuits 110of a top emission-type when seen in the plan view from the viewer side,however, for simplicity, a structure which is formed after the pixelelectrode (anode) in the light emitting element 150 is omitted. In FIG.5, structures up to the pixel electrode of the light emitting element150 are shown, and the structures thereafter are not shown. In addition,hereinafter, in each drawing, reduced scales of each layer, each member,each region, or the like are differentiated in order to set to arecognizable size.

First, as shown in FIG. 5, a substrate 2 as a base is provided withrespective semiconductor layers 130 a and 140 a on which a polysiliconfilm is patterned in a shape of an island. The semiconductor layer 130 aforms the transistor 130, and the semiconductor layer 140 a forms thetransistor 140. Here, the semiconductor layer 130 a is formed in a shapeof a rectangle of which straight side horizontally extends along thescanning line 112 which will be formed later, as shown in FIG. 4 whenseen in the plan view. On the other hand, the semiconductor layer 140 ais formed in the shape of a rectangle of which straight sidehorizontally extends along the data line 114 which will be formed later,when seen in the plan view.

As shown in FIG. 5, a gate insulating layer 10 is provided so as tosubstantially cover the entire surface of the semiconductor layer 130 aand the semiconductor layer 140 a. A gate wiring layer of aluminum ortantalum is provided on the front surface of the gate insulating layer10, and the respective scanning line 112 and gate electrode layer 21 areprovided by patterning the gate wiring layer.

The scanning line 112 extends in the horizontal direction in FIG. 4, hasa branched portion toward the downward direction for every pixel circuit110, and the branched portion thereof is overlapped with the centerportion of the semiconductor layer 130 a. Among the semiconductor layers130 a, the region which overlaps with the branched portion of thescanning line 112 is the channel region 130 c (refer to FIG. 5). Inaddition, in FIG. 5, in the semiconductor layers 130 a, the left side isthe drain region 130 d, and the right side is the source region 130 swith respect to the channel region 130 c.

On the other hand, the gate electrode layer 21 has a shape of arectangular frame in which the upper side, the right side, and the lowerside are integrated without having a left side, as shown in FIG. 4 whenseen in the plan view. Among these, the lower side is overlapped withthe center portion of the semiconductor layer 140 a. Among thesemiconductor layers 140 a, a region which is overlapped with the lowerside of the gate electrode layer 21 becomes the channel region 140 c(refer to FIG. 5). In the semiconductor layer 140 a, in FIG. 5, the leftside is the drain region 140 d, and the right side is the source region140 s with respect to the channel region 140 c.

In FIG. 5, a first interlayer insulating layer 11 is formed so as tocover the scanning line 112, the gate electrode layer 21 or the gateinsulating layer 10. A conductive wiring layer is formed, and relayelectrodes 41, 42, 43, and 44 are respectively formed on the frontsurface of the first interlayer insulating layer 11.

Among these, the relay electrode 41 is connected to the drain region 130d through a contact (via) hole 31 which respectively opens the firstinterlayer insulating layer 11 and the gate insulating layer 10.

In addition, in FIG. 4, a portion where an “x” mark is applied to the“□” mark is a contact hole.

In FIG. 5, one end of the relay electrode 42 is connected to the sourceregion 130 s through a contact hole 32 which respectively opens thefirst interlayer insulating layer 11 and the gate insulating layer 10.On the other hand, the other end of the relay electrode 42 is connectedto the gate electrode layer 21 through a contact hole 33 which opens thefirst interlayer insulating layer 11.

The relay electrode 43 is connected to the source region 140 s through acontact hole 34 which respectively opens the first interlayer insulatinglayer 11 and the gate insulating layer 10. Here, the shape of the relayelectrode 43 when seen in the plan view is a rectangle so as to coverthe upper side of the gate electrode layer 21 as shown in FIG. 4. Forthis reason, the holding capacity 135 has a configuration in which thefirst interlayer insulating layer 11 is interposed between the gateelectrode layer 21 and the relay electrode 43 as shown in FIG. 5.

The relay electrode 44 is connected to the drain region 140 d through acontact hole 35 which respectively opens the first interlayer insulatinglayer 11 and the gate electrode layer 21.

A second interlayer insulating layer 12 is formed so as to cover therelay electrodes 41, 42, 43, and 44 or the first interlayer insulatinglayer 11. A conductive wiring layer is formed on the front surface ofthe second interlayer insulating layer 12, and relay electrodes 61 and62, and the power supply line 116 are respectively formed by patterningthe wiring layer.

Among these, the relay electrode 61 is connected to the relay electrode41 through a contact hole 51 which opens the second interlayerinsulating layer 12. The relay electrode 62 is also connected to therelay electrode 43 through a contact hole 52 which opens the secondinterlayer insulating layer 12.

The power supply line 116 is connected to the relay electrode 44 througha contact hole 53 which opens the second interlayer insulating layer 12.For this reason, the power supply line 116 is connected to the drainregion 140 d through the relay electrode 44. The power supply line 116is formed in the horizontal direction where the scanning line 112extends as shown in FIG. 4 when seen in the plan view.

In addition, the relay electrodes 41 and 61, the relay electrodes 43 and62, and the relay electrode 44 and the power supply line 116 may beconnected to the contact holes 51, 52, and 53 respectively, by fillingup a columnar connection plug which is formed of a high melting pointmetal such as tungsten.

A third interlayer insulating layer 13 is formed so as to cover therelay electrodes 61 and 62, and second interlayer insulating layer 12. Aconductive wiring layer is formed on the front surface of the thirdinterlayer insulating layer 13, and the data line 114, shield wires 81 aand 81 b (not shown in FIG. 5), and a relay electrode 82 arerespectively formed by patterning the wiring layer.

Among these, the data line 114 is connected to the relay electrode 61through a contact hole 71 which opens the third interlayer insulatinglayer 13. For this reason, the data line 114 is connected to a drainregion 130 d following paths of the relay electrodes 61 and 41. Here,the data line 114 is formed in the vertical direction which isorthogonal to the extension direction of the scanning line 112 as shownin FIG. 4 when seen in the plan view.

A relay electrode 82 is connected to the relay electrode 62 through acontact hole 72 which opens the third interlayer insulating layer 13.

In addition, the relay electrode 61 and the data line 114, and the relayelectrodes 62 and 82 may be respectively connected to the contact holes71 and 72, by filling up a columnar connection plug which is formed of ahigh melting point metal.

Each of the shield wires 81 a and 81 b is respectively formedcorresponding to each column as shown in FIG. 4 when seen in the planview.

In detail, a shield wire 81 a on a certain column is formed in thehorizontal direction on the right side of a data line 114 so as to bepositioned between the data line 114 on the column and a transistor 140in a pixel circuit 110 on the column. At this time, the shield wire 81 ais provided to be close to the data line 114 when comparing between thedata line 114 and the transistor 140. That is, the distance between theshield wire 81 a and the data line 114 is set to be shorter than thedistance between the shield wire 81 a and the transistor 140. For thisreason, the shield wire 81 a easily perform the capacitative couplingwith the data line 114 compared to the transistor 140.

On the other hand, a shield wire 81 b on a certain column is formed inthe vertical direction on the left side of a data line 114 so as to bepositioned between a neighboring data line 114 on the right side withrespect to the column and a transistor 140 in a pixel circuit 110 on thecolumn. At this time, the shield wire 81 b is provided to be close tothe data line 114 when comparing between the data line 114 and thetransistor 140. That is, the distance between the shield wire 81 b andthe data line 114 is shorter than the distance between the shield wire81 b and the transistor 140. For this reason, the shield wire 81 beasily perform the capacitative coupling with the data line 114 comparedto the transistor 140.

The shield wires 81 a and 81 b are disposed to be interposed between adata line 114 on the left side and a data line 114 on the right side,however, the shield wire 81 a is disposed before the data line 114 onthe left side and the shield wire 81 b is disposed before the data line114 on the right side, when seen from the transistor 140 in the planview.

In addition, the shield wires 81 a and 81 b are formed in the verticaldirection as shown in FIG. 4, and are extended to the outside of aregion where the pixel circuit 110 is arranged, and are applied with aconstant potential in time, for example, the potential Vel is appliedthereto.

Further, the shield wires 81 a and 81 b may be connected through acontact hole in a portion which intersects with the power supply line116 when seen in the plan view for every one row, or for a couple ofrows.

A fourth interlayer insulating layer 14 is formed so as to cover thedata line 114, the shield wires 81 a and 81 b, and a relay electrode 82,or the third interlayer insulating layer 13. A wiring layer withconductivity and reflectivity is formed on the front surface of thefourth interlayer insulating layer 14, and an anode of the lightemitting layer 150 is formed by patterning the wiring layer. The anodeis an individual pixel electrode for each pixel circuit 110, and isconnected to a relay electrode 82 through a contact hole 92 which opensthe fourth interlayer insulating layer 14. For this reason, the anode(pixel electrode) is connected to the source region 140 s followingpaths of the relay electrodes 82 and 62, and the relay electrode 43which also functions as the other electrode of the holding capacity 135.

In addition, the relay electrode 82 and the pixel circuit may beconnected to the contact hole 92, by filling up the connecting plug ofthe columnar shape which is formed of a high melting point metal.

Further structure of the electro-optical device 1 will not be shown,however, a light-emitting layer which is formed of an organic ELmaterial is laminated to the anode for every pixel circuit 110, and acommon transparent electrode is provided in each pixel circuit 110 as acommon electrode 118 which functions as the cathode, as well. In thismanner, the light emitting element 150 becomes an OLED which interposesthe light-emitting layer with the anode and the cathode which face eachother, emits light with a brightness corresponding to a current whichflows from the anode toward the cathode, and is observed toward thedirection opposite to the substrate 2 (top emission structure). Inaddition to this, sealing glass for cutting off the light-emitting layerfrom the air, or the like, is provided, however, the description thereofwill be omitted.

In addition, in FIG. 4, since a pixel electrode as the anode of thelight emitting element 150 is not shown in the drawing, the contact hole92 only has the “□” mark applied which denotes the position thereof.

Subsequently, a shielding function due to the shield wires 81 a and 81 bwill be described with reference to FIG. 6. FIG. 6 is a diagram whichshows the pixel circuit 110 shown in FIG. 4 for which the planarstructure is replaced with an electrical circuit.

As described above, since the data line 114 of each column is subject topotential fluctuation, noise which is caused by the potentialfluctuation propagates to each part of the pixel circuit 110.

According to the first embodiment, the shield wire 81 a is positionedbefore the gate node g and the source node of the transistor 140 on theith row and jth column when seen from the data line 114 on the jthcolumn. For this reason, the noise generated from the data line 114 onthe jth column is absorbed by the capacitative coupling Ca between theshield wire 81 a and the data line 114 on the jth column.

In addition, the shield wire 81 b is also positioned before the gatenode g and the source node of the transistor 140 on the ith row and jthcolumn when seen from the data line 114 on the (j+1)th column. For thisreason, the noise which is generated from the data line 114 on the(j+1)th column is absorbed by the capacitative coupling Cb between theshield wire 81 b and the data line 114 on the (j+1)th column.

Therefore, according to the electro-optical device 1, it is possible toperform a stable display, since the gate node g and the source node ofthe transistor 140 are not easily influenced by noise which is caused bythe potential fluctuation of the data line 114.

In addition, according to the first embodiment, since the shield wires81 a and 81 b are formed by patterning the same wiring layer as that ofthe data line 114 or the relay electrode 82, additional processes arenot necessary in the manufacturing process.

FIG. 7 is a diagram which shows an equivalent circuit of the pixelcircuit 110 along with the parasitic capacitance of each unit.

In the drawing, C_(Dg) denotes the parasitic capacitance which isgenerated between the drain node D (data line 114) of the transistor 130and the gate node g of the transistor 140, and C_(Ds) denotes theparasitic capacitance which is generated between the drain node D of thetransistor 130 and the source node of the transistor 140.

C_(HOLD) denotes a capacity of the holding capacity 135.

C_(gd) denotes the parasitic capacitance which is generated between thegate node g and the drain node d of the transistor 140 (power supplyline 116), C_(ds) denotes the parasitic capacitance which is generatedbetween the drain node d and the source node of the transistor 140, andC_(OLED) denotes capacitive components of the light emitting element150.

In the pixel circuit 110, the transistor 130 is turned off whencorresponding scanning line is in a non-selection period. In addition,the power supply line 116 and the common electrode 118 have a constantpotential.

For this reason, the pixel circuit 110 in the non-selection period canbe expressed as a simplified model as shown in FIG. 8. In addition, inthe figure, Vamp is potential amplitude of the data line 114 in thenon-selection period.

In this model, a fluctuation portion ΔVgs which is given to the holdingvoltage Vgs of the holding capacity 135 can be expressed as shown in theexpression (1) in FIG. 8. In addition, a coefficient K₁ in theexpression (1) is expressed as shown in the expression (2), and acoefficient K₂ is expressed as shown in the expression (3).

Since the embodiment include the shield wires 81 a and 81 b, therespective parasitic capacities C_(Dg) and C_(Ds) become small comparedto a configuration which does not include the shield wires 81 a and 81b.

For this reason, since the component of (a) in the expression (2), andall components of denominator become large, the coefficient K₁ becomessmall. On the other hand, since the component of (b) in the expression(3), and all component of denominator become large, the coefficient K₂becomes small.

Accordingly, in the embodiment, since the fluctuation portion ΔVgs withrespect to the potential amplitude Vamp becomes small compared to theconfiguration which does not include the shield wires 81 a and 81 b, itis possible to perform a stable display which is not easily influencedby the potential fluctuation of the data line 114, the noise, or thelike.

Here, when the potentials of the gate node g and the source node arefluctuated due to the noise which is caused by the potential fluctuationof the data line 114, in detail, when the fluctuation is actualized as acrosstalk as follows, the display quality is deteriorated.

FIGS. 9A and 9B are diagrams which show an example of the crosstalkwhich is generated in an electro-optical device which does not includethe shield wires 81 a and 81 b of the embodiment.

Here, as shown in FIG. 9A, crosstalk means a phenomenon in which, forexample, when a black rectangular region is displayed on a window with agray background region, in practice, as shown in FIG. 9B, the upperregion (a2) and the lower region (c2) are displayed with different darkgray scale from the other gray regions (a1, a3, b1, b3, c1, and c3) withrespect to the black region (b2).

In addition, in FIGS. 9A and 9B, brightness of the regions is expressedby a density of an oblique line. Further, crosstalk is also generatedwhen the region (b2) is white. In both cases, since the region which isexpressed with different gray scale appears in the up and downdirections of the region (b2), it is sometimes especially referred to asvertical crosstalk.

It is considered that the vertical crosstalk is generated due tofollowing reasons. That is, in a frame, a data line 114 which extendsover the regions (a1, b1, and c1) has a constant potential correspondingto gray scale data over the selection from the first row to the last rowm. For this reason, the pixel circuit 110 which belongs to the regions(a1, b1, and c1) holds the potential which is held in the gate node gdue to a selection of a scanning line which corresponds to the owncircuit, without being influenced by noise from the data line,respectively. The same is applied to a data line 114 which extends overregions (a3, b3, and c3), and a pixel circuit 110 which belongs to theregions (a3, b3, and c3). For this reason, each of pixel circuits 110which belong to the regions (a1, a3, b1, b3, e1, and c3) emit light witha brightness which corresponds to the holing potential of the gate nodeg, in the entire region of a time period corresponding to one frame.

On the contrary, a data line 114 which extends over regions (a2, b2, andc2) has a potential which corresponds to gray gray scale data duringselecting the region (a2), has a low potential which corresponds toblack gray scale data during selecting the region (b2), and returns tothe potential corresponding to the gray scale data during selecting theregion (c2).

For this reason, in the pixel circuit 110 which belongs to the region(a2), even if the circuit holds a potential in which the gate node gcorresponds to gray, due to a selection of a scanning line correspondingto the own circuit, the potential may change due to the noise which iscaused by the potential fluctuation of the data line 114 when selectingthe region (b2).

In addition, since the data line 114 returns to the potentialcorresponding to the gray when selecting the region (c2), the gate nodeg returns to the potential corresponding to the gray due to thereturning of the data line 114. Alternatively, there is a possibility ofapproaching the potential.

However, for example, even if the gate node g returns to the potentialcorresponding to the gray, each of the pixel circuits 110 which belongsto the region (a2) emits light with a brightness corresponding to thepotential which is lowered from the potential corresponding to the gray,during selecting at least the region (b2), in a period corresponding toone frame, after writing.

The same is applied to the region (c2). That is, in the pixel circuit110 which belongs to the region (c2), even if the circuit holds thepotential to which the gate node g corresponds to the gray due to aselection of a scanning line corresponding to the own circuit, thepotential may change by being influenced by the potential fluctuation ofthe data line 114 when selecting the region (b2) in the next frame.

Accordingly, when considering the mean value of a period correspondingto one frame, each of the pixel circuits 110 which belongs to theregions (a2 and b2) is looked dark gray scale differently from each ofthe pixel circuits 110 which belongs to other regions (a1, a3, b1, b3,c1, and c3). It is considered that this is the mechanism in which thevertical crosstalk is generated.

According to the first embodiment of the invention, since each of thegate node g and the source node have a structure which is not easilyinfluenced by noise which is caused by the potential fluctuation of thedata line 114, due to the shield wires 81 a and 81 b, it is possible tosuppress such a vertical crosstalk, and perform a display of highquality.

In addition, according to the first embodiment, the shield wires 81 aand 81 b were set to the same potential Vel as that of the power supplyline 116, however, the shield wires may be held to another potential,for example, to the potential Vet.

Second Embodiment

According to the first embodiment, the shield wires 81 a and 81 b wereformed, by patterning the same wiring layer as that of the data line114, however, the shield wires may be formed of a wiring layer differentfrom that of the data line 114. Therefore, subsequently, as a secondembodiment, an example will be described, in which the shield wires 81 aand 81 b are formed of the same wiring layer as that of the relayelectrodes 61 and 62 which are on the lower side of the data line 114,and the power supply line 116.

FIG. 10 is a plan view which shows a configuration of a pixel circuit110 of an electro-optical device in the second embodiment. FIG. 11 is apartial cross-sectional view of the pixel circuit shown in FIG. 10 whichis cut along line XI-XI.

When forming shield wires 81 a and 81 b from the same wiring layer asthat of relay electrodes 61 and 62, and a power supply line 116, it isnecessary to avoid interference (electrical contact) from the shieldwire 81 a and the relay electrode 61. In detail, it is necessary toprovide a contact hole 51 to the outside (to the left side in FIGS. 10and 11) of the shield wires 81 a when seen in the plan view.

For this reason, in the second embodiment, as shown in FIG. 10, thecontact holes 51 and 71 are arranged so as to be overlapped with eachother at the same location when seen in the plan view, and a relayelectrode 41 is extended to the same location. It is needless to saythat the contact holes 51 and 71 may be arranged at a different locationwhen seen in the plan view, for example, by extending a relay electrode61 to a different location, or the like (now shown in the drawing).

Even in the second embodiment, since the shield wire 81 a is positionedbefore each node of a transistor 140 on the ith row and jth column inthe plan view, when seen from a data line 114 on the jth column, noisewhich is generated from the data line 114 on the jth column is absorbedby a capacitative coupling between the shield wire 81 a and the dataline 114 on the jth column.

In addition, the shield wire 81 b is also positioned before each node ofthe transistor 140 on the ith row and jth column in the plan view, whenseen from the data line 114 on a (j+1)th column, noise which isgenerated from the data line 114 on the (j+1)th column is absorbed by acapacitative coupling between the shield wire 81 b and the data line 114on the (j+1)th column.

For this reason, also in the second embodiment, it is possible toperform a stable display, since it is not easily influenced by noise orthe like.

In addition, in the second embodiment, the shield wires 81 a and 81 bare formed by patterning the same wiring layer as that of the relayelectrodes 61 and 62, and the power supply line 116, it is not necessaryto provide additional processes in the manufacturing process, similarlyto the first embodiment.

Further, in the second embodiment, the shield wires 81 a and 81 b areformed using a wiring layer which is different from that of the dataline 114. For this reason, since the shield wires 81 a and 81 b do notcome into contact with the data line 114, it is possible to make thepitch of the pixel circuit narrow. That is, according to the firstembodiment, since the shield wires 81 a and 81 b are formed of the samewiring layer as that of the data line 114, it is necessary to separatethe shield wires 81 a and 81 b from the data line 114, in order tosecure the shielding function. On the contrary, since it is notnecessary in the second embodiment, even if the shield wires 81 a and 81b are overlapped with the data line 114 when seen in the plan view,since electrical insulating is secured if the shield wires and the dataline are separated at a portion of the relay electrode 61, it ispossible to make the pitch narrow easily.

Meanwhile, if the shield wire is formed to intersect with each node inthe transistor 140 when seen in the plan view, more powerful shieldingfunction is expected. Therefore, an example in which the shield wire isformed of the same wiring layer as that of the data line, and theshielding function is strengthened will be described as a thirdembodiment and a fifth embodiment. In addition, an example in which theshield wire is formed of a wiring layer different from that of dataline, and the shielding function is strengthened will be described lateras a sixth embodiment and a seventh embodiment.

Third Embodiment

FIG. 12 is a plan view which shows a configuration of a pixel circuit110 of an electro-optical device according to a third embodiment. FIG.13 is a partial cross-sectional view of the pixel circuit in FIG. 12which is cut along line XIII-XIII.

As shown in FIG. 12, in the third embodiment, a part of a shield wire 81a is extended toward the right side, and is formed to cover a relayelectrode 43 when seen in the plan view. A holding capacity 135 is aregion where the relay electrode 43 and a gate electrode layer 21 areoverlapped with each other when seen in the plan view. The relayelectrode 43 is the other electrode in the holding capacity 135, andalso is a source node of the transistor 140. For this reason, in thethird embodiment, the shielding function is further strengthenedcompared to the first embodiment.

Fourth Embodiment

FIG. 14 is a plan view which shows a configuration of a pixel circuit110 of an electro-optical device according to a fourth embodiment.

As shown in FIG. 14, shield wires 81 a and 81 b are respectively formedin a strip shape along a data line 114 for every pixel circuit 110, andare respectively connected to a power supply line 116. In addition, inthe fourth embodiment, the shield wires 81 a and 81 b are formed of thesame wiring layer as that of the data line 114. For this reason, theshield wire 81 a is connected to the power supply line 116 through acontact hole 73 which opens the third interlayer insulating layer 13.Similarly, the shield wire 81 b is connected to the power supply line116 through a contact hole 74 which opens the third interlayerinsulating layer 13. In addition, a cross-sectional view thereof will beomitted.

If the shield wires 81 a and 81 b are formed to be one line along thedata line 114, respectively, similarly to the first embodiment, theremay be a case where it is not possible to sufficiently absorb the noise,since the impedances of the shield wires 81 a and 81 b become relativelyhigh, when resistivity thereof is relatively high, or when the shieldwires are separated from a connection point of the constant potential.On the contrary, according to the fourth embodiment, since the shieldwires 81 a and 81 b are provided for every pixel circuit 110, and areconnected to the power supply line 116, it is possible to obtain lowimpedance, and to increase the noise absorbing ability.

Fifth Embodiment

FIG. 15 is a plan view which shows a configuration of a pixel circuit110 of an electro-optical device according to a fifth embodiment. Thefifth embodiment is a combination of the third embodiment and the fourthembodiment, and is formed to cover a relay electrode 43 when seen in theplan view, by changing the shape of the shield wire 81 a shown in FIG.14.

For this reason, according to the fifth embodiment, it is possible toraise the noise absorbing ability, by strengthening a shieldingfunction.

Sixth Embodiment

Similarly to the second embodiment, when a shield wire is formed of awiring layer which is different from that of a data line 114, it ispreferable that the shield wire be provided at the lower side of thedata line 114 so as to be overlapped with the data line 114 when seen inthe plan view, not at both sides of the data line 114.

On the other hand, it was already mentioned in the fourth embodiment(fifth embodiment) that it is possible to raise the noise absorbingability, when the shield wire is connected, for example, to a powersupply line 116 for every pixel circuit 110.

Accordingly, subsequently, a sixth embodiment, as a combination of both,will be described in which a shield wire is formed of a wiring layerwhich is different from that of a data line 114, is provided at thelower side of the data line 114 so as to be overlapped with the dataline 114 when seen in the plan view, and is integrated with the powersupply line 116.

FIG. 16 is a plan view which shows a configuration of a pixel circuit110 of an electro-optical device according to the sixth embodiment, andFIG. 17 is a partial cross-sectional view of the pixel circuit in FIG.16 which is cut along line XVI-XVI.

The shield wires 81 a and 81 b are provided per column in the firstembodiment to fifth embodiment, however, in the sixth embodiment, theshield wires 81 a and 81 b are integrated into one shield wire 81, andalso functions as the power supply line 116.

As shown in FIG. 17, the shield wire 81 which also functions as thepower supply line 116 is one in which a wiring layer formed in thesecond interlayer insulating layer 12 is patterned, along with the relayelectrodes 61 and 62. As shown in FIG. 16, the shape of the shield wire81 when seen in the plan view is that it has a wider width than the dataline 114 so as to overlap with the vertical data line 114, and has alattice shape by being integrated with the horizontal power supply line116.

The data line 114 is connected to the drain region 130 d through therelay electrodes 61 and 41 in order, however, since the shield wire 81is formed of the same wiring layer as that of the relay electrode 61, itis not necessary to avoid the interference. For this reason, the dataline 114 is branched to the right in FIG. 16, and is extended to aportion where the shield wire 81 is not formed. The contact hole 51 isformed at the extended portion, and connects the data line 114 to therelay electrode 61. In this manner, it is possible to electricallyseparate the shield wire 81 and the relay electrode 61 from each otherwithout being interfered.

In addition, in this example, the contact holes 51 and 71 are arrangedto be overlapped with each other at the same location when seen in theplan view. However, the contact holes 51 and 71 may be arranged atdifferent location (not shown in the figure).

Meanwhile, in the sixth embodiment, since the data line 114 is branchedand extended to the right, there is a possibility that the noise mayjump into the gate node g and the source node of the transistor 140 fromthe extended portion. For this reason, in the sixth embodiment, a branchwire 81 d, which is the shield wire 81 extended to the right, isprovided between a branch portion of the data line 114 and the relayelectrode 43 and gate electrode 21, when seen in the plan view. In thismanner, a portion which is extended to the right side of the data line114, that is, noise from the vicinity of the contact hole 71 is absorbedby the branch wire 81 d, before reaching each node of the transistor140.

According to the sixth embodiment, since the shield wire 81 is providedso as to be overlapped with the data line 114 when seen in the planview, and of which potential is fixed by functioning as the power supplyline 116 as well, it is possible to strengthen the shielding function.

Seventh Embodiment

FIG. 18 is a plan view which shows a configuration of a pixel circuit110 of an electro-optical device according to a seventh embodiment.

As shown in the figure, in the seventh embodiment, the shield wire 81which also functions as the power supply line 116 is to cover theholding capacity 135 (gate electrode layer 21) and the transistor 140when seen in the plan view.

As described above, the shield wire 81 (power supply line 116) is formedby patterning the same wiring layer as that of the relay electrodes 61and 62, it is necessary to avoid the interference with the relayelectrodes 61 and 62. In the seventh embodiment, the shield wire 81which also functions as the power supply line 116 has an open shape inthe vicinity region of the relay electrodes 61 and 62.

In addition, the cross-sectional view of the main part of the pixelcircuit 110 in the seventh embodiment will be a view to which theportion which is denoted by the broken line in FIG. 17 is added.

According to the seventh embodiment, the shield wire 81 is provided tobe overlapped with the data line 114 when seen in the plan view, and tocover the holding capacity 135 and the transistor 140. In addition,since the potential thereof is fixed because it functions as the powersupply line 116 as well, the shielding function thereof is furtherstrengthened.

In addition, in the seventh embodiment, the open area of the shield wire81 may be further narrowed as long as it is not interfering with therelay electrodes 61 and 62. Further, in the seventh embodiment, theshield wire 81 is supposed to cover the entire region of the holdingcapacity 135 and the transistor 140 when seen in the plan view, however,it may cover only a part thereof.

Application/Modified Example

The invention is not limited to the above described embodiments, and canbe applied and modified.

For example, in a configuration of the holding capacity 135, the firstinterlayer insulating layer 11 was interposed between the gate electrode21 and the relay electrode 43, however, for example, the gate insulatinglayer 10 may be interposed between a semiconductor layer and the gateelectrode 21, by providing the semiconductor layer to be overlapped withthe gate electrode layer 21, when seen in the plan view. As thesemiconductor layer, a layer in which the source region 140 s isextended may be used, or a layer which is separately patterned may beused. In addition to these, a configuration in which an interlayerinsulating layer or a gate insulating layer is interposed between anelectrode and wiring which are formed of different wiring layer may beadopted. In addition, a plurality of layers which is connected inparallel may be used as the overall holding capacity 135.

In addition, a position to which the holding capacity 135 iselectrically inserted may be a location, for example, between the gatenode g and the common electrode 118 as shown in FIG. 19, in addition toa location between gate node g and the source node of the transistor140. It may be a location between the gate node g and a wiring which isfixed to other potential, even though it is not particularly shown inthe figure.

The driving of the pixel circuit 110 is not limited to a method in whicha data signal of a potential which simply corresponds to gray gray scaledata is held in the gate node g, in a selection period where thetransistor 130 is on state. For example, the driving of the pixelcircuit may be performed such that the data line 114 is set to areference potential in the selection period in which the transistor 130is turned on, a power source due to the power supply line 116 and thecommon electrode 118 is switched between a first potential and a secondpotential, a voltage corresponding to a threshold voltage of thetransistor 140 is held in the holding capacity 135, and after that thedata line 114 becomes a potential which corresponds to the gray grayscale data. In addition, the driving of the pixel circuit may beperformed such that the potential of the data signal is changed in theselection period, and time rate of change of the data signal at the endof selection period is set to a value which corresponds to the gray grayscale data. Further, the driving of the pixel circuit may be performedsuch that a lamp signal is provided to the source node through acapacitive element for every row, and causes a set current to flow tothe transistor 140.

In any driving, it is possible to suppress the fluctuation of thepotential of each node of the transistor 140 which flows a current tothe light emitting element 150, by providing a shield wire of eachembodiment in the pixel circuit 110 due to the noise from the data line114.

In the shield wire, it is preferable to adopt a wiring layer in whichtwo or more different wiring layers are patterned. For example, in thesixth (seventh) embodiment, it is preferable to have a double structureof the shield wire 81 (power supply line 116) and a separately formedshield wire, by patterning the data line 114 and the same wiring layeras that of the relay electrode 82. In addition, in the separate shieldwire, it is preferable to avoid the interference with the data line 114and the relay electrode 82.

As the light emitting element 150, an element which emits light with abrightness corresponding to a current, such as an inorganic EL element,an LED (Light Emitting Diode), or the like may be adopted, in additionto the OLED.

Electronic Apparatus

Subsequently, an electronic apparatus to which an electro-optical deviceaccording to the embodiment of the invention is applied will bedescribed.

FIG. 20 is a diagram which shows the appearance of a personal computerto which the electro-optical device 1 according to the above describedembodiment is adopted as a display device. The personal computer 2000includes the electro-optical device 1 and a main body unit 2010 as adisplay device. The main body unit 2010 is provided with a power supplyswitch 2001 and a key board 2002.

When an OLED is used in a light emitting element 150, in theelectro-optical device 1, it is possible to display a screen of whichviewing angle is wide, and which is easy to view.

FIG. 21 is a diagram which shows the appearance of a mobile phone towhich the electro-optical device 1 according to the above describedembodiment is adopted as a display device. The mobile phone 3000includes an ear piece 3003, a mouth piece 3004, and the above describedelectro-optical device 1, in addition to a plurality of operationbuttons 3001, an arrow key 3002, or the like. By operating the arrow key3002, the screen displayed in the electro-optical device 1 is scrolled.

FIG. 22 is a diagram which shows the appearance of a PDA (PersonalDigital Assistant) to which the electro-optical device 1 is adopted asthe display device according to the embodiment of the invention. The PDA4000 includes the above described electro-optical device 1, in additionto a plurality of operation buttons 4001, an arrow key 4002, or thelike. In the PDA 400, a variety of information such as an address book,a diary, or the like, is displayed in the electro-optical device 1 by apredetermined operation, and the displayed information is scrolledaccording to the operation of the arrow key 4002.

In addition, as electronic apparatuses to which the electro-opticaldevice according to the embodiment of the invention is adopted, forexample, there are a television, a car navigation system, a pager, anelectronic organizer, electronic paper, a calculator, a word-processor,a work station, a TV phone, a POS terminal, a printer, a scanner, a copymachine, a video player, equipment with a touch panel, or the like, inaddition to the equipments exemplified in FIGS. 20 to 22. Particularly,as a micro-display, for example, there are a head-mounted display, adigital still camera, an electronic view finder of a video camera, orthe like.

1-20. (canceled)
 21. An electro-optical device comprising: a scanningline; a data line which intersects the scanning line; a wire appliedwith a constant potential; a light emitting element; a drivingtransistor that controls a current flowing through the light emittingelement, the driving transistor having a first end coupled to the lightemitting element and a second end; a switching transistor which iscoupled between the gate of the driving transistor and the data line,and of which conduction state is controlled according to a scanningsignal which is supplied through the scanning line; and a holdingcapacitor having a first electrode coupled to the first end of thedriving transistor, the wire overlapping at least a part of the firstelectrode of the holding capacitor in plan view.
 22. The electro-opticaldevice according to claim 21, the driving transistor being anN-channel-type transistor.
 23. The electro-optical device according toclaim 21, the holding capacitor coupled between the first end of thedriving transistor and the gate of the driving transistor.
 24. Theelectro-optical device according to claim 21, the wire being providedbetween the driving transistor and the data line in a cross-sectionalview.
 25. The electro-optical device according to claim 21, a distancebetween the wire and the data line being shorter than a distance betweenthe wire and the driving transistor.
 26. The electro-optical deviceaccording to claim 21, further comprising a first power line and asecond power line, the light emitting element and the driving transistorbeing coupled to each other in series in a path between the first powerline and the second power line, and the wire being coupled to one of thefirst power line and the second power line.
 27. The electro-opticaldevice according to claim 26, the wire having a portion which is coupledto the one of the first power line and the second power line.
 28. Theelectro-optical device according to claim 21, the wire being parallelwith the data line.
 29. The electro-optical device according to claim21, further comprising another wire and another data line immediatelyadjacent to the data line, the other wire being provided between thedriving transistor and the other data line, the data line and the otherdata line being provided on opposite sides of the driving transistor inplan view.
 30. The electro-optical device according to claim 21, thewire overlapping the first end of the driving transistor in plan view.31. The electro-optical device according to claim 21, the wire having ashield function.
 32. The electro-optical device according to claim 21,the wire decreasing influences of a noise on a potential of the firstelectrode of the holding capacitor, the noise being caused by apotential fluctuation of the data line.
 33. The electro-optical deviceaccording to claim 21, further comprising a relay electrode coupled tothe first end of the driving transistor and the light emitting element,the wire having an opening, the relay electrode provided in the openingof the wire.
 34. An electro-optical device comprising: a scanning line;a data line which intersects the scanning line; a wire applied with aconstant potential; a light emitting element; a driving transistor thatcontrols a current flowing through the light emitting element, thedriving transistor having a first end coupled to the light emittingelement and a second end; and a switching transistor which is coupledbetween the gate of the driving transistor and the data line, and ofwhich conduction state is controlled according to a scanning signalwhich is supplied through the scanning line, the wire overlapping thefirst end of the driving transistor in plan view.
 35. An electronicapparatus comprising an electro-optical device according to claim 21.36. An electronic apparatus comprising an electro-optical deviceaccording to claim
 22. 37. An electronic apparatus comprising anelectro-optical device according to claim
 23. 38. An electronicapparatus comprising an electro-optical device according to claim 24.39. An electronic apparatus comprising an electro-optical deviceaccording to claim
 25. 40. An electronic apparatus comprising anelectro-optical device according to claim 26.